1. Technical Field
Various embodiments relate to a semiconductor device, and more particularly, a semiconductor device capable of efficiently performing a refresh operation.
2. Related Art
In general, a semiconductor device includes a large number of memory cells. As process technology continues to reduce dimensions and integration density increases, the number of memory cells included in a semiconductor device increases. The large number of memory cells in semiconductor devices may result in a significant probability that there will be at least one defective memory cell in every semiconductor device. Even if a semiconductor device has only one defective memory cell, however, the semiconductor device may malfunction.
To avoid the need to discard semiconductor devices having relatively few defective memory cells, techniques have been developed to repair memory cells. Therefore, in order to increase the yield of the product, the semiconductor device includes redundancy memory cells as well as normal memory cells.
The semiconductor device may include a redundancy control circuit. If defective memory cells are detected and marked as defective through a test procedure, the redundancy control circuit may connect redundant elements instead of the defective memory cells when an access request for the normal memory cell is made. The redundancy control circuit may replace the defective memory cell (hereafter “repair target memory cell”) with a redundancy memory cell.
Specifically, when a request for accessing any of the repair target memory cells is made during a read/write operation, a redundancy memory cell may be accessed instead of the repair target memory cell.
Thus, even when accessing the address of the repair target memory cell (hereafter, referred to as “failed address”), a normal operation of the semiconductor device is guaranteed by accessing the redundancy memory cell instead of the repair target memory cell (hereafter, referred to as “repair operation”).
Electrically programmable fuses such as Array Electrical-fuse (“ARE”) may store (program) information by applying a high electric field to a gate of a transistor to rupture a gate dielectric layer. The electrically programmable fuses may be used to set a specific value determined during a semiconductor integrated circuit test process. In particular, the electrically programmable fuses may be used to store the address (hereafter, referred to as “redundancy address”) of the redundancy memory cell replacing the failed address.